Friedrich Zöllner, as it was more commonly known, was a famous astrophysicist and professor at the University of Leipzig, Germany. He was born in Berlin on November 8, 1834, and died prematurely in Leipzig (Germany) on April 25, 1882, at the age of 48 years old. He left behind him numerous works in the fields of astronomy and physics, optics, where it became very well known for his research on optical illusion. His work on optics, developed in 1860, received the name of the illusion of Zöllner, in which parallel lines appear as diagonals.

In the field of astronomy, he emphasized to prove the theory of Christian Doppler on the effect of the movement in the color of the electromagnetic radiation of the stars as a result of the deviation of the lines in the spectrum of the light emitted by these celestial bodies. He invented a highly sensitive apparatus called Astrofotómetro, capable of measuring these variations. In his honor, one of the craters of the Moon received the name of the crater Zöllner. In 1872 he was invited to occupy the chair of Astrophysics at the University of Leipzig.

He was a member of the Royal Society of England, the Royal Astronomical Society of London, the Imperial Academy of Physical and Natural Sciences of Moscow and the Scientific Society of Studies Psychics of Paris. From a very young age, Zöllner is interested in the phenomena mediúmnicos. When presented with the opportunity, in 1875, he travelled to England to visit one of the greatest scientists of the era, William Crookes, who was a figure more prominently in the investigation of the so-called "effects mediúmnicos", as the motion of objects without the interference of a power source and the materialization of spirits. Zöllner was looking for a scientific explanation to these phenomena.

After his visit, he developed a theory about the occurrence of these phenomena. According to his theory, the universe has, in addition to three-dimensional space euclidean, a fourth dimension through which they can be explained to some spiritual phenomena. According to this theory, the phenomena mediúmnicos could lose their mystical character and move to the domain of physics and the philosophy of the ordinary. For a better understanding of what is the 4th dimension in the conception of modern physics, let us suppose that the space can bend in the proximity of large bodies gravity, which can only be done in the direction of the 4th dimension, and all the phenomena mediúmnicos, as well as the displacement of spiritual entities, would be made by the 4th dimension. On the theory of the 4th dimension, Schiaparelli, a famous Italian astronomer, wrote in a letter to Camille Flammarion: "it Is the theory most ingenious and likely you can imagine."

To further confirm his theory, Zöllner held numerous meetings with mediums and researchers in their own home. In 1877, he was first in Leipzig in the medium of English Henry Slade. Slade was the protagonist of many manifestations of physical effects. To analyze the mediumship of Slade, and attended occasionally with the help of other university professors, which added excitement to their research.

As a result of your work with this medium, Zöllner published several articles in scientific journals and, later, books, on "physical transcendental". Like Slade, Zöllner studied the phenomena produced by Madame D'esperance, the protagonist of appearances and transport of objects. In march of 1880, the baron Von Hoffmann invited to the medium of English William Eglinton to participate in meetings with Zöllner. There were 25 sessions in total. Eglinton was a medium of physical effects, mainly materialization and direct writing. Zöllner was very satisfied with the results of their research, and even had the intention to publish a book about his experiences, but he died before that happened.

Zöllner was a great fighter for the spiritist cause, noted for his physical experiments in which the action of spirits left no room for doubt or uncertainty. As a physicist, he used this science to demonstrate immortality and to divulge the interference of disincarnated spirits in the daily life of incarnated spirits. By proposing the theory of the 4th dimension to explain observed phenomena, he anticipated today's physicists and demonstrated how science can help religion and how religion can be scientific.

(...) The offering of his book Scientific Evidence of Survival or Physical Transcendental William Crookes, Zöllner wrote a dedication in a very expressive of the which we extract the following passage: "With the highest sense of gratitude and recognition for the services that he has rendered a new science, I offer you, respetabilísimo colleague, the third volume of my Scientific Treatises.

By a remarkable coincidence, our scientific investigations have been found in the same field, providing the much-admired humanity a new class of physical phenomena that loudly proclaiming the existence of another material world of intelligent beings. Please accept this work as a sign of gratitude and sympathy of the honest heart of a German". Friedrich Zöllner: astronomer, physicist, professor, scientist, researcher, a pioneer of the theory of the 4th dimension in the Universe. It is another example of how science and spirituality can go hand in hand.

He was a scientist who has passed through the confines of the laboratories earthly to reach the heights of philosophy of science itself, becoming a hunter of truths, truths that fuel the dreams immortal humanity.